Apparatus for the control of highway-crossing signals



088. '18, 1930. M. GILSON 1,784,868

APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING SIGNALS I Original Filed July 29 1,92

INVENTOR 2 Ma m Patented Dec. 16, 1930 uurrre srArEs PATENT OFFICE ROBERT M. GILSON, OF PITTSBURGH, PENNSYLVANIA, 'ASSIG'NOR TO THE UNION SWITCH (it SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA APPARATUS FOR THE CONTROL OF HIGHWAY-CROSSING SIGNALS Application filed July 29, 1926, Serial No. 125,761. Renewed March 20, 1930.

My invention relates to apparatus for the control of highway crossing signals, that is, of signalslocated at intersections of railways and highways, and designed to indicate to those using the highway whether or not a train is approaching on the railroad.

I will describe one form of apparatus embodying my invention, and will then point out the novelfeatures thereof in claims.

The accompanying drawing is a diagrammatic View showing one form of apparatus embodying my invention.

Referring to the drawing, the reference characters 1 and 1 designate the track rails of a stretch of railway track along which traffic normally moves in the direction inclicated by the arrow. These rails are divided by insulated joints 2 into a plurality of track sections of which only one section A.B is shown in the drawing. A highway M intersects the railway track in section A-B.

Section AB is provided with a track circuit comprising a transformer C having its secondary connected across the rails at the exit end of the section, and a track relay D receiving current from the rails at the entrance end of the section; The primary of the transformer C is constantly supplied with alternating current from a suitable source which is not shown in the drawing.

At a point G a considerable distance to the right of the highway M, the primary 3 of a transformer H is connected across the rails, and the secondary 4 of this transformer is connected with a control relay R It will be seen, therefore, that this relay is energized by current received from the track c1rcuit when the section is not occupied by a train. At a point J adjacent the highway M, two insulatedajoints 2 are inserted in the track rails 1 and 1 respectively. The, reference character L designates a'transforiner having two primaries 5 and 6 and a secondary 7L The primary 5 is connected with the rail 1 around the joint 2 in this rail, and

primary 6 is connected with the rail l around the joint 2 in this rail. The secondary 7 of transformer L is connected with a second control relay R Relay R is therefore energized by the current flowing in the track circuit when there is no .train between point J and point A. Furthermore, the primary windings 5 and 6 of the transformer L transmit track circuit current around the joints 2, and so this transformer eliminates the necessity for dividing the section AB into two track sections with an individual track circuit for each section. i

The control relays R and R govern a signal relay E, which latter relay is provided with a pick-up circuit and a stick circuit. The pick-up circuit for relay E is from battery F, through back contact 8 of relay R front contact 9 ofrelay R and winding of relay E to battery F. The stick circuit for relay E is from battery F,through back contact 8 of relay R back contact 10 of rela R front contact 11 of relay E and the wine ing of relay E to battery F.

Located adj acent the highway is a high- 7 way crossing signal of the three-aspect wigwag type, provided as usual with an operating circuit and with a holding circuit. The operatingcircuit is from battery F,through the operating mechanism of the signal K and back to battery F. The main holding circuit for signal K is from battery F, through front contact 12 of relay R and the operating mechanism of signal K to battery F. This operating circuit is provided with a shunt around contact 12of relay R which shunt is frombattery F, through back contact 8 of relay R back contact 13 of relay R front contact 14 of relay E to the operating mechanism of signal K.

The operation of the apparatus is as follows: When the track section AB is unoccupied, both control relays R and R are energized, so that the holding circuit for signal K is closed at contact 12 of relay B and both the pick-up and the stick circuits. for

relay E are open at back contact 8 of relay- R When a train passes through the section and approaches the point G, it reduces the amount of current supplied to the relay R so that this relay opens, and the opening of contact 12Isets the signal K into operation.

The closing of back contact 8 of relay R completes the piclnup circuit for relay E, so a t is r ay e omes: energized. Sig..-

nal K continues in operation until the train bridges the insulated joints 2* at the point J, thereby tie-energizing relay R The closing of back contact 10 of relay R completes the stick circuit for relay E, so that this relay remains energized even though contact 9 opens. The closing of back contact 13 of relay R completes the shunt for the holding circuit ofsignal K, so that the operation of this signal ceases. Relays R and It remain tie-energized until the train leaves section AB whereupon these relays again become energized and relay E opens.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track intersected by a highway, two normally energized control relays associated with said stretch and arranged to be successively de-energized as a train passes through the stretch, a signal relay, a pick-up circuit for said signal relay including a backcon tact of the control relay first de-energized' by a train passing throughthe stretch and a front contact of the other control relay,, a stick circult for said signal relay IIIClHCling a back contact of each of said control relays, and a signal for said highway controlled by said stick relay. 7

2. In combination, a stretch of railway track intersected by a highway, two normally energized control relays associated with said stretch and arranged to be successively de-energized as a train passes through the stretch, a signal relay, a pick-up circuit for said signal relay including a back contact of the control relay first de-energized by a train passing through the stretch and a front contact of the other control relay, a stick circuit for said signal relay including a back contact of each of said control relays, and a signal for said highway controlled jointly by said signal relay and by said control relays.

3. I11 combination, a stretch of railway track intersected by a highway, two normally energized control relays associated with said stretch and arranged to be successively deenergized as a train passes through the stretch, a signal relay, a pick-up circuit for said signal relay including a back contact of the control relay first de-energized by a 1 train passing through the stretch and a front contact of the other control relay, a stick circuit for said signal relay including a back contact of each of said control relays, a sig nal for said highway, a holding circuit for said signal includinga front contact of the control relay first operated by a train passing through the stretch, and a branch for adjacent the highway, a second transformer having two primaries connected around said two joints respectively and a secondary supplying current to a second control relay, and a signal for said highway controlled by said control relays.

5. In combination, a section of railwaytrack intersected by a highway and provided with a track circuit including a source of current connected across the rails, a transformer having its primary connected across the track rails at a distance from the highway in the direction from which trains approach the highway, a control relay connected with the secondary of said transformer, an insulated joint in each track rail adjacent the highway, a second transformer having two primaries connected around said two joints respectively and a secondary supplying current to a second control relay, a stick relay controlled by said control relays, and a signal for said highway governed jointly by said stick relay and by said control relays.

6. In combination, a section of railway track intersected by a highway and provided with a track circuit, two normally energized control relays receiving energy from said track circuit and arranged for successive deenergization as a train passes through the section each relay remaining de-energized until the train leaves the section, a signal relay, a pick-up circuit for said signal relay including a back contact of the control relay first de-energized by a train passing through the section and a front contact of the other control relay, a stick circuit for said signal relay including back contacts of both 'of said con trol relays, and a signal for said highway controlled jointly by said control relays and said signal relay.

7. In combination, a section of railway track provided with an insulated joint in at least one track rail, a source of track circuit current connected across the railsof said sec tion, current conducting means connected in series with said one rail to conduct current aroundsaid joint, a relay energize'd'by the flow of track circuit current in said current I conducting means, a highway intersecting said track, and a highway crossing signal for said intersection controlled in part by said relay.

8. In combination, a section of railway track provided with an insulated joint in at least one track rail, a source of track circuit currentconnected across the rails of said section, current conducting means connected in series with said one rail. to conduct current around said joint, circuit controlling means governed by the flow of track circuit current in said current conducting means, a highway intersecting said track, and a highway crossing signal for said intersection controlled in part by said circuit controlling means.

9. In combination, a section of railway track provided with an insulated joint in at least one track rail, a source of alternating track circuit current connected across the rails of said section, a transformer the primary of which is connected in series with said one rail to conduct current around said insulated joint, a relay connected with the secondary of said transformer, a highway intersecting said track, and ahighway crossing signal for said intersection controlled in part by said relay.

10. In combination, a section of railway track provided with an insulated oint in each rail, a source of alternating track circuit current connected across the rails of said section, a transformer having two primaries one connected in series with one rail around the joint therein and the other connected in series with the other rail around the joint therein, a relay connected with the secondary of said transformer, a highway intersecting said track, and a highway crossing signal for said intersection controlled in part by said relay.

11. In combination, a section of railway track, a source of energy connected across the rails adjacent one end of the section, an insulated joint in one rail of the section, a wind ing connected across said joint, a relay normally supplied with energy by said winding, and a trackway signal controlled by such winding.

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12. In combination, a section of railway track, a track circuit for said section including the rails of the section in series and a source of energy connected across the rails adjacent one end of the section, a winding connected in series with the track circuit at an intermediate point in the section so as to be normally energized and to be deenergized when the section is occupied by a train be tween such winding and said one end of the section but not when the section is occupied by a train between such relay and the other end of the section, a relay normally supplied with energy by said winding, and a signal controlled by the relay.

13. In combination, a section of railway track, a source of alternating current connected across the rails adjacent one end of the section, an insulated joint in one rail of the section, a transformer having one winding connected across said joint, a second winding on said transformer, a relay receiving energy from said second winding, and traffic governing means controlled by said relay.

14. In combination, a section of railway track, a highway crossing said section, a source of alternating current connected across the rails adjacent one end of-the section, an insulated oint in one rail, a transformer having one winding connected across said insulated joint, a second winding on the transformer, a relay receiving energy from said second winding, and a highway crossing sig nal located adjacent said crossing and controlled by said relay.

In testimony whereof I afiix my signature.

ROBERT M. GILSON. 

